Struggling here, and this doesn't seem like it should be so difficult (or frustrating, or. . .). Any help or insight will be greatly appreciated.

I'm trying to unlock an iPhone 3G iOS 4.2.1 bb 5.15.04 using RedSn0w 0.9.10b5 (and b4 and lower versions).

Short story: when I get to the point in RedSn0w where it detects that the iPhone is DFU, RedSn0w crashes. Happens on my toshiba laptop w win 7 and my crappy netbook win xp HE sp3.

I am running RedSn0w as administrator. I can't set affinity on the win 7 laptop. I can and did on the crappy netbook (check cpu0, uncheck cpu1).

These RedSn0w versions were downloaded from iclarified. Win 7 laptop has iTunes 10.5.3.3; crappy netbook has iTunes 10.5.2.11.

Using iPhone1,2_4.2.1_8C148_Restore.ipsw from iclarified.

Suggestions?!

You're using the wrong version of redsn0w. This is a common problem. redsn0w is NOT backwards compatible, each version of redsn0w targets specific iOS versions. Newer versions of redsn0w do NOT automatically jailbreak all older versions of iOS. The version needed to jailbreak iOS 4.2.1 is redsn0w 0.9.6b5.

n1ckn4m3, you are the man. Worked like a charm! I read a good bit and still managed to miss that detail. . .thank you!

No prob at all. They're not REALLY forthcoming with that, it's a pretty common mistake because it does stand to reason that a newer version would jailbreak older versions. Glad to hear this was the issue!